Process of fractionally distilling mixtures containing hydrocarbons



E. H. FRENCH. PROCESS 0F FRACTIONALLY DISTILLLNG MIXTURES CONTAININGHYDRDCARBONS.

APPUcAT'loN HLED JULY lo, 1949.

Patented Oct. 18, 1921.

DKRNSR nwkl @2530s 34a/vento@ dwdrdHFrench w' f gaxip MHoIr/MWS UNITEDSTATES PATENT OFFICE.

EDWARD H. FRENCH, OF. KINGSPORT, TENNESSEE.

Specification of Letters Patent.

Patented Oct. 18, 1921.

apiiucation filed July io, 1919. serial No. 309,848.

To all whom it may concern:

Be it known that I, EDWARD H. FRENCH, a citizen of the United States,residing at Kingsport, in the county of lSullivan and State ofTennessee, have invented a certain new and useful Improvement in Processof Fractionally Distillin Mixtures Containing Hydrocarbons, of which thefollowing isa specification.

- It is desirable and often necessary in evaporating or distillingcertain products to reduce the temperature at which evaporation ordistillation takes place, in order to'prevent the decomposition ofeither the distillate or residue, and the consequent formation ofobjectionable or@ secondary products. The

formation 'of such decomposition products takes place in the evaporationand distilla` tion of many'substances, such as petroleum, coal tar andpyroligneous acid. The solid coke residue found in petroleum and coaltar stills under ordinary distillation being a well known illustration.

In the attempt to lessen or preventthis decomposition several differentmethods of distillationand evaporation are used, for example, vacuumdistillation and evaporation, steam distillation and` passing air or gasthrough a liquid, thus reducing its evaporatwhich is equal to or abovethe boiling point ing point. While these methods may lessenobjectionable decomposition yet considerable does take place in thedistillation and evaporation of many substances.

In the ordinary methods of distillation the material is maintained inthe heat zone continuously thereby causing a maximum decomposition. Inmy process this is avoided.

The rate of evaporation and distillation is dependent upon the amount ofsurface of liquid. In the ordinary methods the time required for thevaporization of any fraction is necessarily so long asv to allow ofpbjectionable decomposition in the remaining material. In my process Isecure a maximum surface by finely dividing the liquid supplied to thestill by means of atomization.

In addition, I aid evaporation by means of the gas used in atomizing theliquid into the still body. The distillation may also be promoted with avacuum.. As before indicated in progressively removing the distillationfractions in the usual methods employed it is necessary to maintain theentire mixture at a progressively increasing temperature of the fractiondistilled. In my process as herem particularly described I am able tovaporize each fraction at a point below its average boiling point in themixture, the higher lfractions immediately dropping out of the heat zonewhich includes the pre-A heater and still body, thus preventing thedecomposition caused by the continuous heating of the mixture.

I am thus able to combine-and utilize'live important physical conditionswhich effect evaporation and distillation, (l) .low temperature ofevaporation, (2)v continuous removal of material from the heat zone,(3)' a maximum surface forvevaporation, (4) the carrying properties of agas, `(5) aid with a vacuum when desired.

As will be explained my process is of particular value in fractionaldistillation of complex mixtures such as petroleum,. in which thevarious fractions can be removed progressively, without the usualdecomposition and consequent vformation of permanent gases. Infractionating petroleum or'other mixtures the temperature of thepreheater in my process is made to conformrto the boiling points of thecomponents of the constituents of the mixture. In all instances thistemperature is below the boiling point of the fraction to be removed.

In the accompanying illustrations- Figure 1 shows diagrammaticallytheapparatus that may be used in carrying out the process.

Fig. 2 is a detail of one of the atomizers.

The character E designates the body of a still equipped with atomizingor 'spraying nozzles D. At G is a catcher or chamber having a balile Rand catcher G placed in the vapor line for removing vany large particlesof entrained matter. is a vapor line to condenser 'I which leads to.receivers J and J which receive the distillate. O' is a vapor line forthe non-condensing vapors ,and atomized vapors leading to vacuum volwhere atomiza'tion by gas is used would notv be required. F and F arereceivers for the reception of that fraction which is notvolatilized inthe first spraying and from which pump B again pumps or circulates theliquor.

In practice the product to be distilled is drawn from the storage tankthrough pump B into receiver A where it is pumpe through heater C thencethrough nozzle D into chamber E. In said chamber the lower fractions arevolatilized and passed through catcher G through vapor line H andcondenser I andthence into tank J or J', all of which are under vacuumproduced by pump K. The higher fraction which is not volatilized dropsdown in chamber F or F. After all the material in A `has passed through`chamber E and the higher fraction removed and its residue passed into For F the valve at Q, is closed and the valve Q2 opened to supply thematerial to be pumped to A and F acts as a receiver for the second ornext progressive residue. In this manner and by regulating the speed ofentrance of material into chamberv E and the tempera-A ture of heater Can accurate fractionationcan be secured. From the construction shown itwill be observed that because the.

mixture is passed in a continuous stream through the preheater C only a.relatively small volume of: the mixture is subjected to heat at onetime, and since the heat of the preheater C and heater Gr can beregulated, the mixture can be subjected to just that degree of heatnecessary to vaporizel 'and remove the fraction desired to be distilled,thereby avoiding decomposition either of the mixture itselr1 or of thefraction to be removed. Moreover, the separating rocess is accelerated,and a fraction neary free from added decomposition products obtained andthe decomposition of the residue prevented. Because the average boilingpoint varies in different mixtures of hydrocarbons, no specific boilingpoint for any of the fractions could be stated, hence in the practicaluse of the process, the heat to be used is-determined and regulated ineach instance by observing the distillate from the condenser. When, forexample, in distilling gasolene from crude oil,'the run from thecondenser shows the materialv to meet commercial requirements, the rateof flow and temperature are set to continue the production of the sameuntil the fraction is r moved Jfrom the whole.

In initiating the process the air is first exhausted from the system ofapparatus through pipe P and then valve P is closed and the valve P24opened so that upon the operation of pump M gas is taken from tank L andreturned to tank L through valve P2.

A valve at Cf can be closed When reservoir A is charged.

A check' valve at C2 prevents the return of liquid` from reservoir A'.

Other valves and conventional parts can be employed as shown.

The forms of theparts used in carrying out the process can be. changedwithout departingv from the gist of the invention as i claimed.

upon atomization with an inert gas, imme` diately subjecting the thusheated mixture to such atomization with an inert gas in a separatingchamber, condensing the vaporized fraction and promptly removing theresidue from saidvchamber.

2. In the process of fractionally distilling a complex liquid mixturecontaining hydrocarbon, heating such liquid in` transit from a reservoirto a temperature below the average boiling point of the fraction to -bedistilled while in the mixture but sufficiently to vaporize suchfraction upon atomization in a vacuumized separator, immediatelysubjecting the thus heated mixture to atomization in a-vacuumizedseparating chamber, condensing the vaporized traction and promptlyremoving the residue from said chamber.

3. In the process of fractionally distilling a complex liquid mixturecontaining hydrocarbon, heating such liquid in transit from a 'reservoirto a temperature below the average boiling point of the fraction to bedistilled while in the mixture but suiiiciently to vaporize suchfraction from the mixture upon atomization with an inert gas,immediately subjecting the thus heated mixture to such atomization withan inert gas, infan -unheated separating chamber, condensing thevaporized fraction and romptly removing the residue from said c amber.

4. In the process of fractionally distil'li-ng a complex liquid mixturecontaining hydrocarbons, heating such liquid in transit from a reservoirto a temperature'below the average boiling point of the `fraction to bedistilled while in the mixture but suiiciently to vaporize such fractionfrom the mixture upon atomization with an inert gas, iinmediatelysubjecting the thus 4heated mixture to atomization with an inert gas ina vacuumized separating chamber, condensing the vaporized fractionandpromptly removing the residue from said chamber.

5. In the process of ractionally distilling a complex liquid mixturecontaining hyrocarbons, heating such liquid to a temperature below theaverage boiling point of the iso v:traction to be distilled While in themixture but suiiciently upon atomization With an inert gas to vaporizesuch fraction from the mixture, atomizing the same with an inert gas ina vacuumized chamber, condensing liquid to a temperature belo'w theaveragel boiling point of the fraction to be distilled While in themixture but sufficiently to vaporize such fraction from the mixture uponatomization in a vacuumized chamber, immediately subjecting the thusheated mixture to atomization in a vacuumized separating chamber,condensing the vaporized .fraction and promptly removing the residuefrom said chamber. A s,

7. The process of fractionally distilling a complex liquid mixturecontaining hydrocarbons consisting in passing the liquid in a streamthrough a heater adapted to heat the liquid to a temperature below theaverage boiling point of the fraction to be distilled While in themixture but sufficiently to vaporize such fraction from the mixture uponatomization with an inert gas, immediately subjecting the thus heatedmixture to atomization Withan inert gas in a separating chamber,condensing the vaporized `fraction and promptly removing the residuefrom said chamber.

8. The process of fractionally distilling aV complex liquid mixturecontaining hydrocarbons consisting in passing the liquid in a streamthrough a heater adapted to heat the liquid to a temperature below theaverage boiling point of the fraction to be distilled While in themixture but sufiiciently to vaporize such fraction from the mixture uponatomization with an inert gas, immen diately subjecting the thus heatedmixture to atomization with an inert gas in a vacuumized separatingchamber, condensing the vaporized fraction and promptly removing theresidue from said chamber.

EDWARD H. FRENCH.

